What Causes Depression?

By Lauren Krouse

Researchers are still learning what causes depression, but we do know there’s not one set cause. Depression often is a result of a combination of factors. There are some things that can increase the chances someone will experience depression, including:

• Biology: There are chemicals in your brain — such as serotonin and dopamine — that directly affect your mood and how you process emotions. How brains produce and use these chemicals is different for different people, and it can increase the chance you could have depression. 
• Family history: Having parents or siblings with depression can put you at higher risk.
• Feeling isolated or rejected from friends or family: LGBTQIA+ teens, for example, are more likely to experience isolation or a lack of acceptance from friends and family — as well as harassment and violence as they grow up — which puts them at risk of developing depression and other mood disorders. It has nothing to do with who they are and everything to do with how they are treated by others.
• Childhood trauma: Growing up in a stressful environment can increase your risk of experiencing a mental health condition. Adverse childhood experiences (ACEs), such as having abusive or neglectful caregivers or growing up with an adult who struggles with a mental health condition or alcohol or drug use, can increase your risk of depression.
• Other health conditions: Chronic illness, chronic pain, anxiety, and attention-deficit hyperactivity disorder (ADHD), among other conditions, sometimes co-occur with depression. Other conditions, such as an underactive thyroid (hypothyroidism), can sometimes look like depression. Certain medications can also cause depression symptoms as a side effect.
• Substance use: It’s not uncommon to use alcohol or drugs to cope or self-medicate when you’re struggling emotionally, but it can increase your risk of depression and make it harder to know if your treatment is working.

Learn more about depression from the National Alliance on Mental Illness (NAMI). 

Who Gets Depressed?

Depression can sometimes make you feel alone, but you’re not. Anyone can experience depression, and about 280 million people around the world are living with it. Research also shows that depression is on the rise.

Young adults between the ages of 18 and 24 are the most likely age group to report having major depression. Some teen and young adult groups are more likely to struggle with depression, including: 

• Girls and young women. Girls and young women are nearly three times as likely as boys and young men to report that they struggle with depression. This could be linked to hormonal changes that impact how the brain responds to stress, as well as stress related to work, relationships, gender norms, bullying, and sexual harassment.   
• Native American, Native Alaskan, and multiracial teens. Native and multiracial teens report experiencing higher rates of moderate to severe depression than their peers of other races. Ongoing struggles and stress due to trauma passed down generation to generation, growing up without enough money for necessities, and lack of access to health care have been linked to high rates of depression, mental health conditions, and suicide in these communities.
• LGBTQIA+ teens. Gay, lesbian, and bisexual teens are twice as likely to experience ongoing sadness or hopelessness than their straight peers. Transgender youth are twice as likely to report symptoms of depression, and are more likely to have suicidal thoughts or attempt suicide than their cisgender peers. Harassment, unfair treatment based on identity, being denied opportunities, and family rejection all make it more likely that someone could experience depression as a result.

Different groups also experience depression in different ways. According to research compiled by NAMI, Black individuals may be more likely to report physical, rather than emotional, symptoms of depression and other mental health challenges, such as physical pain, compared to white individuals. Symptoms can also differ between adolescent girls and boys. Girls are more likely to report fatigue, guilt, worthlessness, poor concentration, and sadness. Boys more likely to experience irritability, sleep disturbance, and lack of pleasure.

All of Us Deserve Support

If you suspect you or someone you love could be depressed, don’t let fear of judgment, the belief that you can get through this on your own, or other obstacles keep you from getting the help you need. Everyone needs help sometimes, especially when you’re struggling. 

Getting help for depression is self-care, and you have options. You can also be the bridge a loved one needs to connect with a health-care provider.

Learn more about depression and how to get the help you — or someone you care about — needs:

What’s the Difference Between Sadness and Depression?

How Do I Know If It’s Depression?

Different Types of Depression: What’s the Difference Between Mild, Moderate, and Severe?

How Is Depression Diagnosed and Treated?

6 Tips for Managing Depression

What Is the Connection Between Suicide and Depression?

How Can I Help Someone Who Seems Depressed?

How to Tell Someone I’m Depressed and Ask for Help